Part 1: Hydrogen and Turbomachinery

https://www.conceptsnrec.com/blog/hydrogen-and-turbomachinery

Part 1: Hydrogen and Turbomachinery

By Dr. David Schowalter, Sr. Director, Global Software Sales
Jan 3, 2023

 

Because of its promise as a non-polluting fuel, hydrogen is currently a very popular topic among the energy and turbomachinery communities. If hydrogen is reacted with pure oxygen, the thermal energy release is significant, and water is the only by-product. This highly exothermic reaction was used to get humanity to the moon. Of course, nitrous oxides (NOx) can be released if hydrogen is burned in air. If, on the other hand, the energy from the reaction is converted to heat and electricity in a fuel cell, then only water vapor is discharged. In addition, when pressurized in a tank, hydrogen is an easily transportable fuel, and so is desirable for transportation.

수소가 순수 산소와 반응하면 열에너지 방출양이 중요하고 유일한 부산물은 물이다. 물론 수소가 공기 중에 연소되면 질소 산화물은 방출되지만 에너지는 열과 전기로 전환될 수 있고 오직 물만 배출된다. 추가로 압축을 하면 수소는 쉽게 운반가능하고 운송에도 적합하다. 

 

 

Critics correctly point out that hydrogen is not an energy source. Because it is so highly reactive with oxygen, it is very rare in its elemental form. It takes energy to produce it, so hydrogen is really an energy storage and transportation method. When considering the carbon footprint, it is important to understand the ultimate power source. Natural gas can be used to generate hydrogen in a process called steam methane reforming. Thermo-chemical hydrogen generation can be accomplished with high temperature advanced nuclear reactors, or with solar thermal power. Electrolysis (essentially a reverse fuel cell electrochemical process) can use electricity and water to generate hydrogen, and if this is done using solar photovoltaics or wind energy, then the hydrogen has no carbon footprint. Readers may have seen the “color” of hydrogen referenced, and it is the ultimate energy source that determines the color: green hydrogen is made with renewables or non-carbon emitting sources, blue hydrogen is made with fossil fuels, but the carbon is captured and sequestered, and grey hydrogen is made with fossil fuels without any sequestration.

비평가들은 수소가 에너지원이 아니라는 점을 지적합니다. 산소와의 반응성이 매우 높기 때문에 원소 형태로 존재하는 경우는 매우 드뭅니다. 수소를 생산하려면 에너지가 필요하므로, 수소는 실제로 에너지를 저장하고 운반하는 방법입니다. 천연가스는 증기 메탄 개질이라는 공정에서 수소를 생성하는 데 사용될 수 있습니다. 열화학적 수소 생산은 고온의 첨단 핵 반응기나 태양열 발전을 통해 달성될 수 있습니다. 전기분해(기본적으로 역연료 전지 전기화학 공정)는 전기와 물을 사용하여 수소를 생성할 수 있으며 이것이 태양광 발전이나 풍력 에너지를 사용하여 수행되는 경우 수소는 탄소 발자국이 없습니다.

There are several ways in which the hydrogen economy will impact the turbomachinery industry: combusting hydrogen in gas turbines, turbomachinery for electric vehicles, incorporating hydrogen in pipelines, and hydrogen processing/transportation.

수소가 터보머시너리 산업에 미칠 영향

Gas turbines:
The existing infrastructure for burning small amounts of hydrogen mixed with natural gas in gas turbines for power generation is largely in place now. Current equipment can handle up to about 5% of hydrogen in natural gas pipelines without causing embrittlement. Some advanced projects are burning up to 20% hydrogen currently. The primary impact on the gas turbine operation is in the combustor, and the rotating machinery needs no design modification for small amounts of hydrogen.

Turbomachinery for fuel cell vehicles:
Within the vehicle, hydrogen is carried in an on-board pressurized tank, but an air compressor is needed. Range and efficiency will be critical.

Pipelines:
As mentioned above, up to 5% hydrogen is feasible for existing gas pipelines and associated pipeline compressors. Pure hydrogen pipelines exist today, but only for very localized usage. Long range hydrogen pipelines are probably many years away from becoming a reality.

Processing and associated infrastructure:
Hydrogen production processes require compression. The compressors used are often driven by turboexpanders in another part of the process cycle. Additionally, turbomachinery is needed in hydrogen transportation, where boil-off gas (BOG) is created due to thermal conduction of the liquid hydrogen during transport. Compressors recompress and liquify the BOG to conserve hydrogen. It is these processing and transportation applications that represent the most immediate opportunity for turbomachinery companies.

In Part 2, CTO Mark Anderson takes a more in-depth look at designing hydrogen turbomachinery.